Methods and systems for detecting clamping or firing failure

ABSTRACT

Systems and methods are provided for detecting failure in clamping of a material and/or firing of a staple into a clamped material and indicating such failure to a user on a user interface. The system and methods are particularly suited for use with end effectors having closing and/or firing mechanisms coupled to an actuator. By monitoring a driving parameter of an actuator that effects the clamping and/or firing, the systems and methods provide an indication of failure in response to the monitored drive parameter. In some embodiments, an indication of failure is output when the monitored drive parameter is outside an acceptable range of desired driving parameters during clamping and/or firing. The disclosed systems and methods are particularly beneficial when used for minimally invasive surgery.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a non-provisional of, and claims the benefitof U.S. Provisional Patent Application No. 61/443,148, filed Feb. 15,2011, the entire contents of which are incorporated herein by reference.

The present application is related to U.S. application Ser. No.12/705,418 entitled “Cut and Seal Instrument,” filed on Feb. 12, 2010;U.S. Provisional Application No. 61/260,907, entitled “END EFFECTOR WITHREDUNDANT CLOSING MECHANISMS,” filed on Nov. 13, 2009; U.S. ProvisionalApplication No. 61/260,903, entitled “WRIST ARTICULATION BY LINKEDTENSION MEMBERS,” filed on Nov. 13, 2009; U.S. Provisional ApplicationNo. 61/260,903, entitled “WRIST ARTICULATION BY LINKED TENSION MEMBERS,”filed on Nov. 13, 2009; U.S. Provisional Application No. 61/260,915,entitled “SURGICAL TOOL WITH A TWO DEGREE OF FREEDOM WRIST,” filed onNov. 13, 2009; and U.S. Provisional Application No. 61/260,919, entitled“MOTOR INTERFACE FOR PARALLEL DRIVE SHAFTS WITHIN AN INDEPENDENTLYROTATING MEMBER,” filed on Nov. 13, 2009; each of which is incorporatedherein by reference in its entirety.

BACKGROUND OF THE INVENTION

Minimally invasive surgical techniques are aimed at reducing the amountof extraneous tissue that is damaged during diagnostic or surgicalprocedures, thereby reducing patient recovery time, discomfort, anddeleterious side effects. As a consequence, the average length of ahospital stay for standard surgery may be shortened significantly usingminimally invasive surgical techniques. Also, patient recovery times,patient discomfort, surgical side effects, and time away from work mayalso be reduced with minimally invasive surgery.

A common form of minimally invasive surgery is endoscopy, and a commonform of endoscopy is laparoscopy, which is minimally invasive inspectionand surgery inside the abdominal cavity. In standard laparoscopicsurgery, a patient's abdomen is insufflated with gas, and cannulasleeves are passed through small (approximately one-half inch or less)incisions to provide entry ports for laparoscopic instruments.

Laparoscopic surgical instruments generally include an endoscope (e.g.,laparoscope) for viewing the surgical field and tools for working at thesurgical site. The working tools are typically similar to those used inconventional (open) surgery, except that the working end or end effectorof each tool is separated from its handle by an extension tube (alsoknown as, e.g., an instrument shaft or a main shaft). The end effectorcan include, for example, a clamp, grasper, scissor, stapler, cauterytool, linear cutter, or needle holder.

To perform surgical procedures, the surgeon passes working tools throughcannula sleeves to an internal surgical site and manipulates them fromoutside the abdomen. The surgeon views the procedure by means of amonitor that displays an image of the surgical site taken from theendoscope. Similar endoscopic techniques are employed in, for example,arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy,cisternoscopy, sinoscopy, hysteroscopy, urethroscopy, and the like.

Minimally invasive telesurgical robotic systems are being developed toincrease a surgeon's dexterity when working on an internal surgicalsite, as well as to allow a surgeon to operate on a patient from aremote location (outside the sterile field). In a telesurgery system,the surgeon is often provided with an image of the surgical site at acontrol console. While viewing an image of the surgical site on asuitable viewer or display, the surgeon performs the surgical procedureson the patient by manipulating master input or control devices of thecontrol console. Each of the master input devices controls the motion ofa servo-mechanically actuated/articulated surgical instrument. Duringthe surgical procedure, the telesurgical system can provide mechanicalactuation and control of a variety of surgical instruments or toolshaving end effectors that perform various functions for the surgeon, forexample, holding or driving a needle, grasping a blood vessel,dissecting tissue, or the like, in response to manipulation of themaster input devices.

Non-robotic linear clamping, cutting and stapling devices have beenemployed in many different surgical procedures. For example, such adevice can be used to resect a cancerous or anomalous tissue from agastro-intestinal tract. Unfortunately, many known surgical devices,including known linear clamping, cutting and stapling devices, haveopposing jaws that may generate less than a desired clamping force,which may reduce the effectiveness of the surgical device. Devices havebeen developed generating higher levels of clamping forces forapplicable surgical procedures (e.g., tissue stapling), however,clamping with high force jaws periodically fails. Additionally, firingof staples to seal tissue may fail. Detecting failure in clamping orfiring of a staple has proven difficult in some minimally invasivesurgical applications, however, since a surgeon may not have a clearview of the tissue being clamped or stapled and a tool inserted into abody is constrained by significant size and space limitations. Since asurgeon's tactile feedback in a robotic system can be somewhat limited,a surgeon may not realize when failure has occurred until after theclamping or firing procedure is complete. In light of the above, itwould be desirable to enable a surgeon to detect clamping or failure atthe time it occurs, so that the procedure can be suspended or modifiedto reduce the likelihood of tissue damage and/or to allow the surgeon tomitigate the effects of any tissue which has been damaged. Given thelimitations associated with a minimally invasive surgical environment,it would be desirable to detect failure from outside the body withoutsubstantially adding to the profile of the end effector.

Thus, methods and system which can detect failure and indicate failureto the user, yet are compatible with the demands of minimally invasiveprocedures are desirable. Such tools may be beneficial in surgicalapplications, particularly in minimally invasive surgical applications.

BRIEF SUMMARY OF THE INVENTION

Improved systems and methods to detect and indicate clamping and/orstaple firing failure are provided. The claimed methods and systemsrelate to detecting whether clamping of a material grasped between jawsor firing of a staple into the clamped material is likely to fail. Theclaimed systems and methods may detect failure in clamping or firingduring the process of clamping or firing, thereby reducing the potentialfor tissue damage from continuing to clamp or fire a staple afterfailure has occurred. The claimed systems and methods are particularlyuseful in surgical applications involving clamping of a body tissuebetween two jaws of an end effector and firing of a staple into theclamped tissue. Many surgical applications require clamping of a bodytissue at a clamping force sufficient for cutting, sealing and/orstapling of the clamped tissue. Since clamping and firing of a staplemay require relatively higher forces than tissue manipulation, failurein clamping or firing may potentially cause damage to the delicatetissues. The present methods and systems are particularly advantageousin minimally invasive surgical applications as they indicate failure assoon as it occurs and allows for detection of failure from outside thebody. While the various embodiments disclosed herein are primarilydescribed with regard to surgical applications, these surgicalapplications are merely example applications, and the disclosed endeffectors, tools, and methods can be used in other suitableapplications, both inside and outside a human body, as well as innon-surgical applications.

In a first aspect, the invention provides a method of detecting failurein clamping of a material between jaws driven by a motor or detectingfailure in firing of staple, the firing force being driven by anactuator, such as a motor. The method includes monitoring a driveparameter of the actuator or motor during application of a clamping orfiring force and, in response to the monitored drive parameter,outputting an indication on a user interface of clamping or firingfailure. Typically, an indication of clamping or firing failure occurswhen the monitored drive parameter of the actuator, such as a torqueoutput of a motor or displacement of a driving mechanism, is outside anacceptable range of drive parameters. The indication may also beindicative of a likelihood of clamping or firing failure, wherein thelikelihood of failure falls within a gradient between a first and secondlikelihood, the first likelihood being likely failure and the secondlikelihood being likely success. In many embodiments, the materialclamped and stapled is a body tissue, including an outer skin orinternal organs, such as a bowel, stomach or lung.

In many embodiments, the methods and systems include monitoring a driveparameter during clamping between a first and second jaw of an endeffector or during firing of a staple into clamped tissue. Often, theclamped tissue is cut after opposing sides of the tissue along thecutting line are stapled by a row of surgical staples to seal thetissue. The end effector is generally part of a minimally invasiverobotic surgical system. The first and second jaw may comprise twoseparate jaws or a first jaw articulable against a portion of the endeffector, in which case the portion of the end effector comprises thesecond jaw. In one aspect, the methods include clamping of a materialbetween the first and second jaw of an end effector or firing of astaple into the clamped material, typically in response to a commandfrom a user to clamp or fire. The system effects clamping or firing byapplying a clamping force to a clamp or firing force to a staple. As theclamping or firing occurs, the system monitors the drive parameter ofthe actuator applying the clamping or firing force. In response to themonitored drive parameter, the system outputs an indication on a userinterface of clamping or firing failure or the clamping or firingsuccess.

In many embodiments, an indication of likely clamping or firing failureis provided in response to the monitored drive parameter being outsidean acceptable range of desired drive parameters of the actuator, such asa range of torque outputs. Often, the acceptable range of driveparameters vary with the displacement of the actuator or motor, suchthat the acceptable range of drive parameters may be different dependingon the configuration of the end effector. For example, the acceptablerange of drive parameters at an initial displacement of the actuator ormotor (as the clamp starts from an open configuration) may be differentfrom the acceptable range of drive parameters at a final displacement(such as when the clamp is in a closed/clamped configuration). The sameis true for the different initial configuration and final configurationof the firing mechanism. The system may detect the configuration of theend effector by sensing the displacement of the actuator effectingmovement, or the mechanism through which the actuator effects clampingor firing. The clamping or firing is effected by the drive parameterthrough one or more mechanisms coupling the actuator to the end effectorand/or the staple. The mechanism(s) may include a cable, a hypotube, ora leadscrew. In many embodiments, the indication of likely clampingfailure is a visual indicator shown on a display of a user interface,but may also be communicated to the user by an audio signal, visualsignal, or other sensory indicator.

In another aspect, a method or system may suspend driving of theactuator in response to an indication of failure or likely failure inclamping or firing of the staple. The methods may also includemaintaining a driving parameter after an indication of failure, ormaintaining a driving parameter driving clamping while suspending aforce driving firing of a staple. In many embodiments, the clampingmechanism is non-backdriveable such that no input is needed to maintainthe clamping force once it is applied or established. In such cases, aninput may be needed to unclamp and reverse the motion of the leadscrew.The methods may include reversing a driving force so as to unclamp afteroutputting the indication of failure.

In many embodiments, the system includes an end effector, a sensor, anda user interface. A first and second jaw of the end effector are coupledto an actuator such that driving the actuator produces a clamping forceso as to clamp a material between the first and second jaws. The systemmay also include an actuator, such as a motor, releasably coupled to astaple such that driving the actuator produces a firing force so as tofire the staple into the body tissue. The clamping and firing actuatormay be a single actuator or may be separate actuators. The system mayinclude a sensor for monitoring the drive parameters applying theclamping or firing forces to the end effector. The sensor may be aseparate sensor or may be incorporated into the robotic surgical systemand may also monitor a displacement of the motor or mechanism. Thesystems may also include a processor for comparing the monitored driveparameter with a desired drive parameter or range of parameters. Theprocessor may also determine the range of acceptable drive parametersfor a given displacement.

The system may comprise a first and second actuation mechanism foreffecting clamping and firing, respectively. The first and secondactuation mechanisms can employ different force transmission mechanismscorresponding with the force requirements for the clamping mode and thefiring force mode. For example, a force used by the first jaw actuationmechanism to move the jaw from the open to the close position caninclude a linear force or a torque, and a force used by the second jawactuation mechanism to fire a staple through the tissue can include atorque. In many embodiments, the first actuation mechanism includes aleadscrew-driven mechanism for use in the high force clamping mode, andthe second actuation mechanism includes a second leadscrew-drivenmechanism for use in the firing of the staple. Alternatively, theclamping and firing may utilize a portion of or the same mechanism.

For a fuller understanding of the nature and advantages of the presentinvention, reference should be made to the ensuing detailed descriptionand accompanying drawings. Other aspects, objects and advantages of theinvention will be apparent from the drawings and detailed descriptionthat follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a minimally invasive robotic surgery systembeing used to perform a surgery, in accordance with many embodiments.

FIG. 2 is a perspective view of a surgeon's control console for arobotic surgery system, in accordance with many embodiments.

FIG. 3 is a perspective view of a robotic surgery system electronicscart, in accordance with many embodiments.

FIG. 4 diagrammatically illustrates a robotic surgery system, inaccordance with many embodiments.

FIG. 5A is a front view of a patient side cart (surgical robot) of arobotic surgery system, in accordance with many embodiments.

FIG. 5B is a front view of a robotic surgery tool.

FIG. 6A is a perspective view of an end effector having an articulatedjaw, in accordance with many embodiments.

FIG. 6B is a perspective view of the end effector of FIG. 6A (with thearticulated jaw removed to better illustrate leadscrew actuationmechanism components), in accordance with many embodiments.

FIGS. 7A and 7B illustrate components of a leadscrew actuationmechanism, in accordance with many embodiments.

FIG. 8A illustrates components of a cable actuation mechanism, inaccordance with many embodiments.

FIG. 8B is a perspective view of the end effector of FIG. 8A with aportion of the articulated jaw removed to show cable actuation mechanismcomponents disposed behind the articulated jaw, in accordance with manyembodiments.

FIGS. 8C through 8F illustrate opposite side components of the cableactuation mechanism of FIG. 8A.

FIG. 9A is a perspective view illustrating a cable actuation mechanism,showing a cable used to articulate the jaw towards a clampedconfiguration, in accordance with many embodiments.

FIG. 9B is a perspective view illustrating the cable actuation mechanismof FIG. 9A, showing a cable used to articulate the jaw towards an openconfiguration.

FIG. 10 is a cross-sectional view illustrating components of a leadscrewactuation mechanism, in accordance with many embodiments.

FIG. 11 is a simplified diagrammatic illustration of a tool assembly, inaccordance with many embodiments.

FIG. 12 is a simplified diagrammatic illustration of a robotic toolmounted to a robotic tool manipulator, in accordance with manyembodiments.

FIG. 13 is a diagrammatic view of a telerobotic surgical system, inaccordance with many embodiments.

FIGS. 14A-14B illustrate the user interface assembly having an clampingfailure indicator, in accordance with many embodiments.

FIGS. 15A-15B illustrate examples of indicators of clamping failureindicators, in accordance with many embodiments.

FIGS. 16A-16B illustrates exemplary motor torques during clamping ascompared to a range of acceptable motor torques which vary with motordisplacement, in accordance with many embodiments.

FIGS. 17-20 illustrate methods, in accordance with many embodiments.

FIGS. 21-22 illustrate flow charts utilizing methods in accordance withmany embodiments.

DETAILED DESCRIPTION

Improved systems and methods related to clamping and/or fastener firingare provided. The present invention relates to providing an indicator ofwhether clamping of a given material fails during clamping. Theinvention may be used in systems having jaw members for clamping amaterial or firing of a staple into a clamped material. The claimedsystem and methods are particularly useful for minimally invasivesurgical applications, as they allow for failure detection inconstrained environments from outside the body. Such systems ofteninclude end effectors having jaws that clamp a body tissue and fire astaple into the tissue at a relatively high force. Clamping at a highclamping force allows the user to perform various procedures requiring ahard clamp. For example, a physician may require a hard clamp of bodytissues before cutting, sealing or stapling of tissue. Firing of staplesor other fasteners may also require use of relatively high forces todrive the staple through the body tissue. Since clamping and staplefiring utilize relatively high forces applied in a confined surgicalarea, clamping or firing failure has the potential to damage delicatetissues. The claimed methods and systems are advantageous as they allowdetection of clamping or firing failure during the clamping or firingprocess from outside the body without increasing the profile of the endeffector. Such methods and systems allow for increased capabilities andsafety for the patient while maintaining the reduced scale of theminimally invasive surgical tools. While the various embodimentsdisclosed herein are primarily described with regard to surgicalapplications, these surgical applications are merely exampleapplications, and the disclosed systems and methods can be used in othersuitable applications, both inside and outside a human body, as well asin non-surgical applications.

Typically, a system utilizing the claimed invention includes an endeffector having two jaws for clamping a material and/or firing a stapleor fastener through the clamped material. The two jaws may comprise anarticulated jaw attached to an end effector, such that moving thearticulated jaw towards a portion of the end effector, the second jawbeing that portion of the end effector. In many embodiments, the systemuses two independent mechanisms to articulate the jaws of the endeffector. A first actuation mechanism provides a fast response/low forcemode that varies the position of the articulated jaw between a closed(grasped) configuration and an open configuration. In many embodiments,the first actuation mechanism is back-drivable. For example, in the lowforce mode grasping mode the first actuation mechanism can be designedto provide 5 lbs of clamping force between the tips of the first andsecond jaw. A second actuation mechanism provides a high clamping forcemode for clamping the body tissue between the jaws at the higherclamping force. Often, the second actuation mechanism isnon-back-drivable. The second actuation mechanism converts a relativelyweak force or torque (but with large displacement available) to arelatively high torque rotating the jaw of the end effector. The secondactuation mechanism can be designed to provide, for example, 50 poundsof clamping force between the tips of the clamped jaws.

Typically, in applications using the claimed methods, a surgeon clampsthe body tissue at the relatively high clamping force and once clamped,fires a series of staples through the clamped tissue thereby sealing thetissue. Periodically, the jaws may fail to clamp the tissue, potentiallyresulting in damage to the tissue. Clamping of the tissue may fail for avariety of reasons, including too much tissue being grasped orinsufficient tissue grasped between the jaws, including interferencefrom an adjacent tissue, such as a bone, or slippage of the tissue frombetween the jaws. Even if clamping is successful, firing of a staple orother fastener may fail for a variety of reasons, including a jammedstaple, inconsistencies in the material, interference from anothermaterial, or slippage of the clamped material. Therefore, it would beadvantageous for systems and methods that can detect when clamping orfiring failure occurs during the process of clamping or firing andindicate such failure to a physician, thereby reducing the likelihoodthat tissue damage will result. Ways in which tissue damage can beavoided by use of the claimed methods, include: terminating the clampingor firing process or allowing the user to terminate or modify theprocess after failure has been indicated. The described systems andmethods detect such failures and provide an indication to the user offailure or likely failure during clamping and/or staple firing into aclamped material. Clamping may be considered successful when in theclamped position, the distance between the jaws are sufficient forperforming a therapy, such as firing a staple through the clampedtissue. This distance may vary according to various factors, includingthe type of tissue, type of treatment, or the dimensions of a staple tobe fired through the clamped tissue. In one aspect, the claimed methodsand systems detect failure by monitoring a drive parameter of anactuator or motor that drives the clamping and/or staple firing. In apreferred embodiment, the motor provides a drive parameter or forceoutput, such as a torque, to a mechanism so as to effect clamping and/orfiring of a staple with the end effector. The system may determinewhether the drive parameter is within an acceptable range of desireddrive parameters. The acceptable range of drive parameters may varyaccording to the displacement of the motor or the mechanism effectingmovement. Typically, if clamping or firing fails the force output of thedriving motor drops below a minimum acceptable, such as from an absenceof material between clamping jaws, or the force output may spike above amaximum acceptable force, such as from clamping on a bone or jamming ofthe mechanism. Continuing driving of the motor in either case may resultin damage to surrounding materials or tissue. By monitoring the forceoutput of the driving motor during clamping of the material and/orfiring into the tissue, the claimed methods and systems detect failureor likely failure during clamping or firing and output an indication ofsuch failure or likely failure to the user. Additionally, the system andmethods may automatically terminate the clamping or firing or wait forfurther input from the user after providing an indication of failure.Ideally, the methods include monitoring a drive parameter duringclamping or staple firing, and providing an indication of the likelihoodof clamping or firing failure in response to the monitored driveparameter.

Minimally Invasive Robotic Surgery

Referring now to the drawings, in which like reference numeralsrepresent like parts throughout the several views, FIG. 1 is a plan viewillustration of an embodiment of the present invention. FIG. 1illustrates a Minimally Invasive Robotic Surgical (MIRS) system 10,typically used for performing a minimally invasive diagnostic orsurgical procedure on a Patient 12 who is lying down on an Operatingtable 14. The system can include a Surgeon's Console 16 for use by aSurgeon 18 during the procedure. One or more Assistants 20 may alsoparticipate in the procedure. The MIRS system 10 can further include aPatient Side Cart 22 (surgical robot), and an Electronics Cart 24. ThePatient Side Cart 22 can manipulate at least one removably coupled toolassembly 26 (hereinafter simply referred to as a “tool”) through aminimally invasive incision in the body of the Patient 12 while theSurgeon 18 views the surgical site through the Console 16. Tool assembly26 includes end effector 25, the end effector having jaws for clampingthe tissue and a mechanism for firing a staple through the clampedtissue. An image of the surgical site can be obtained by an endoscope28, such as a stereoscopic endoscope, which can be manipulated by thePatient Side Cart 22 so as to orient the endoscope 28. The ElectronicsCart 24 can be used to process the images of the surgical site forsubsequent display to the Surgeon 18 through the Surgeon's Console 16.Electronics Cart 24 includes a Processor 27 for monitoring the driveparameter provided by the motor output to the end effector. Processor 27may monitor the drive parameter by comparing the drive parameter to anacceptable range of drive parameters. As the acceptable range of driveparameters may vary with the displacement of the motor or the mechanismeffecting movement of the end effector, the Processor 27 may alsoreceive displacement data as to the displacement of the motor or the endeffector mechanism during clamping and/or firing such that Processor 27compares the monitored drive parameters against a range of acceptabledrive parameters for any given displacement. The displacement data maybe measured directly or may be determined from positional data, orderivatives thereof, obtained by the robotic system, such as a roboticpatient-side manipulator (PSM) system, for example, described in U.S.Patent Application Publication No 2007/0005045, the entire contents ofwhich are incorporated herein by reference. In response to the monitoreddrive parameter, Processor 27 may output a clamping failure indicationto a user interface. The system 10 then communicates an indicator of theprediction to the physician on the Surgeon's Console 16 so as tocommunicate to the surgeon whether clamping or firing has failed.

FIG. 2 is a perspective view of the Surgeon's Console 16. The Surgeon'sConsole 16 includes a left eye display 32 and a right eye display 34 forpresenting the Surgeon 18 with a coordinated stereo view of the surgicalsite that enables depth perception. The Console 16 further includes oneor more input control devices 36, which in turn cause the Patient SideCart 22 (shown in FIG. 1) to manipulate one or more tools. The inputcontrol devices 36 will provide the same degrees of freedom as theirassociated tools 26 (shown in FIG. 1) so as to provide the Surgeon withtelepresence, or the perception that the input control devices 36 areintegral with the tools 26 so that the Surgeon has a strong sense ofdirectly controlling the tools 26. To this end, position, force, andtactile feedback sensors (not shown) may be employed to transmitposition, force, and tactile sensations from the tools 26 back to theSurgeon's hands through the input control devices 36.

The Surgeon's Console 16 is usually located in the same room as thepatient so that the Surgeon may directly monitor the procedure, bephysically present if necessary, and speak to an Assistant directlyrather than over the telephone or other communication medium. However,the Surgeon can be located in a different room, a completely differentbuilding, or other remote location from the Patient allowing for remotesurgical procedures (i.e., operating from outside the sterile field).

FIG. 3 is a perspective view of the Electronics Cart 24. The ElectronicsCart 24 can be coupled with the endoscope 28 and can include Processor27 to monitor the drive parameter and to determine an indication ofclamping failure in response to the monitored drive parameter. Processor27 may also process captured images for subsequent display, such as to aSurgeon on the Surgeon's Console, or on any other suitable displaylocated locally and/or remotely.

FIG. 4 diagrammatically illustrates a robotic surgery system 50 (such asMIRS system 10 of FIG. 1), in which the Processor 58 and Display 60 aredepicted separately from Electronics Cart 56 and Surgeon's Console 52.As discussed above, a Surgeon's Console 52 (such as Surgeon's Console 16in FIG. 1) can be used by a Surgeon to control a Patient Side Cart(Surgical Robot) 54 (such as Patent Side Cart 22 in FIG. 1) during aminimally invasive procedure. In preparation for firing a staple to seala body tissue, the Surgeon can command the tool of the Patient Side Cart54 to clamp between jaw members of an end effector. In response to thiscommand, Processor 58 can command the system to begin driving the motorto engage a mechanism that begins moving the jaws together and increasea clamping force to a desired clamping force. As the jaws begin movingtogether and the clamping force increases, the Processor 58 continuouslymonitors a drive parameter of the motor and compares the drive parameterto an acceptable range of drive parameters as the motor drives the jawsto clamp at a desired clamping force. If at any point during clamping,the drive parameter exceeds or drops below an acceptable driveparameter, Processor 58 may output the indication of clamping failure onthe user interface. In response to detection of clamping failure,Processor 58 may also command additional functions, such as suspendingdriving of the motor, preventing firing of the staple, maintaining theclamping force at the point of detected clamping failure, waiting foruser input, and unclamping the tissue. Similarly, the Processor 58continuously monitors the drive parameter during firing of a staplethrough successfully clamped tissue. In response to the drive parameterfalling outside the acceptable range of desired drive parameters,Processor 58 may output a failure indication on the user interface. Inresponse to detected firing failure, Processor 58 may command otherfunctions, such as terminating firing, suspending driving of the motor,maintaining clamping of the tissue while preventing firing, or waitingfor user input.

One of skill in the art would appreciate that an indication of clampingfailure may include an indication of how likely clamping failure may be.For example, the Processor 58 may output an indication of clampingfailure indicating the likelihood of clamping failure from a 0% chanceof failure to a 100% chance of failure, thus allowing the user to adjustor terminate the procedure before actual failure occurs based on anincrease in the likelihood of failure as indicated by the failureindication. In some embodiments, if the monitored drive parameter iswithin the acceptable range of drive parameters, then a failureindicator that express a likelihood of failure may express a likelihoodof failure that falls within a range of 0 to 49%. In another embodiment,this range may be expressed as a gradient, including a non-numericalgradient, such as a color gradient. Depending on the likelihood offailure as communicated by the failure indicator, the Surgeon may thensafely proceed with clamping of the body tissue or may abort clampingand reposition the jaws until Display 60 indicates a higher likelihoodof clamping or firing success.

FIGS. 5A and 5B show a Patient Side Cart 22 and a surgical tool 62,respectively. The surgical tool 62, one of the surgical tools 26, is anexample of an end effector having a set of jaw members for clamping atissue and firing a staple into the clamped tissue. The Patient SideCart 22 shown provides for the manipulation of three surgical tools 26and an imaging device 28, such as a stereoscopic endoscope used for thecapture of images of the site of the procedure. Manipulation is providedby robotic mechanisms having a number of robotic joints. The imagingdevice 28 and the surgical tools 26 can be positioned and manipulatedthrough incisions in the patient so that a kinematic remote center ismaintained at the incision so as to minimize the size of the incision.Images of the surgical site can include images of the distal ends of thesurgical tools 26 when they are positioned within the field-of-view ofthe imaging device 28.

Tissue Clamping and Staple Firing with Independent Actuation Mechanisms

In many embodiments, two independent actuation mechanisms are used tocontrol the articulation of an articulated jaw of an end effector. Afirst actuation mechanism can be used to provide a high force clampingmode, and a second actuation mechanism can be used to provide a highforce firing mode. In many embodiments, the first and second actuationmechanism used to provide the high clamping force and high firing forceis non-back-drivable. The first and second actuation mechanisms maycomprise a first and second leadscrew. Using independent actuationmechanisms may be beneficial in some surgical applications, for example,electrocautery sealing, stapling, etc., that may require differentforces for different functions during the same procedure.

In many embodiments, actuation of the jaws in the high clamping forcemode is provided by a leadscrew actuation mechanism that includes aleadscrew driven cam. The driven cam interfaces with a mating camsurface on the articulated jaw so as to hold the articulated jaw in aclosed (clamped) configuration when the leadscrew driven cam is at afirst end of its range of motion. In addition, the driven cam does notconstrain motion of the articulated jaw when the leadscrew driven cam isat a second end (opposite end) of its range of motion. In other words,the mating cam surfaces are arranged such that motion of the leadscrewdriven cam in one direction will cause the articulated jaw to close, andmotion of the leadscrew driven cam in the reverse direction will allow(but not force) the articulated jaw to open to a limit provided by thecam surfaces. Often, the leadscrew actuation mechanism isnon-back-drivable. In many embodiments, the position of the jaw membersof the end effector can be determined by the position of the cableactuation mechanism, or if driven by a leadscrew, the position of theleadscrew. The system may include a dual drive motor having a drive foreffecting clamping at a clamping force and a drive for effecting firinga staple at a firing force. The motor may utilize an existing motor ordrive, or utilize an additional drive or motor, to effect firing of thestaple. The claimed methods and systems monitor the drive parameter ofwhichever motor, or motors, which are driving the clamping or firing.Additionally, terminating or stopping driving of the motor when failureis detected may also comprise continuing driving of another drive ormotor effecting another function. For example, if firing failure isindicated, the system may stop driving the firing force, while stillmaintaining the driving of the clamping force and wait for a user tounclamp the tissue.

FIG. 6A is a perspective view of an end effector 70 having a jaw 72articulated by two independent actuation mechanisms, in accordance withmany embodiments. The end effector 70 includes an end effector base 74,the articulated jaw 72, and a detachable stationary jaw 76, which holdsthe staples. The end effector 70 is actuated via a first drive shaft 78,a second drive shaft 80, and two actuation cables (not shown). The firstdrive shaft 78 rotates a leadscrew 82 of a leadscrew actuationmechanism, the leadscrew 82 located within the stationary jaw 76. Thesecond drive shaft 80 rotates another leadscrew (not shown) of thedetachable stationary jaw 76.

In many embodiments, the first drive shaft 78 and/or the second driveshaft 80 are driven by drive features located in a proximal tool chassisto which the end effector 70 is coupled with via an instrument shaft. Inmany embodiments, the proximal tool chassis is configured to bereleasably mountable to a robotic tool manipulator. In many embodiments,the first drive shaft 78 and the second drive shaft 80 are actuated viarespective drive features located in the proximal tool chassis. In manyembodiments, such drive features are driven by motors that are locatedin the proximal tool chassis.

FIG. 6B is a perspective view of the end effector 70 of FIG. 6A (withthe articulated jaw 72 removed to better illustrate components of theleadscrew actuation mechanism), in accordance with many embodiments. Theleadscrew 82 is mounted for rotation relative to the end effector base74. A leadscrew driven cam 84 is coupled with the leadscrew 82 so thatselective rotation of the leadscrew 82 can be used to selectivelytranslate the leadscrew driven cam 84 along a cam slot 86 in the endeffector base 74. The end effector 70 includes a pivot pin 88 that isused to rotationally couple the articulated jaw 72 with the end effectorbase 74.

FIGS. 7A through-10 illustrate the actuation mechanisms by which an endeffector clamps a body tissue between its jaws clamping mode and fires astaple into the clamped tissue.

FIGS. 7A and 7B illustrate the leadscrew actuation mechanism of FIGS. 6Aand 6B. The leadscrew 82 has a distal journal surface 96 and a proximaljournal surface that interfaces with a proximal bearing 98. In manyembodiments, the distal journal surface 96 is received within acylindrical receptacle located at the distal end of the cam slot 86.Such a distal support for the leadscrew 82 can be configured to keep theleadscrew 82 from swinging excessively, and with relatively largeclearance(s) between the distal journal surface 96 and the cylindricalreceptacle. The proximal bearing 98 is supported by the end effectorbase 74 so as to support the proximal end of the leadscrew 82. Theproximal bearing 98 can be a ball bearing, which may help to reducefriction and wear. A distal bearing (not shown) can be supported by theend effector base 74 so as to support the distal end of the leadscrew82, and the distal bearing can be a ball bearing. The leadscrew drivencam 84 includes a threaded bore configured to mate with the externalthreads of the leadscrew 82. The leadscrew driven cam 84 includes topand bottom surfaces configured to interact with corresponding top andbottom surfaces of the cam slot 86. The interaction between leadscrewdriven cam 84 and the cam slot 86 prevents the leadscrew driven cam 84from rotating relative to the cam slot 86, which causes the leadscrewdriven cam 84 to translate along the cam slot 86 in response to rotationof the leadscrew.

The articulated jaw 72 includes mating cam surfaces 94 that areconfigured so that the position of the leadscrew driven cam 84 along thecam slot 86 determines the extent to which the rotational motion of thearticulated jaw 72 around the pivot pin 88 is constrained by theleadscrew driven cam 84. The articulated jaw 72 includes a firstproximal side 100 and a second proximal side 102 that are separated by acentral slot. The first and second proximal sides are disposed onopposing sides of the end effector base 74 when the articulated jaw 72is coupled with the end effector base 74 via the pivot pin 88. Each ofthe first and second proximal sides 100, 102 includes a recessed areadefining a mating cam surface 94 and providing clearance between theleadscrew driven cam 84 and the proximal sides 100, 102. When theleadscrew driven cam 84 is positioned at or near the proximal end of thecam slot 86 (near its position illustrated in FIGS. 7A and 7B), contactbetween the leadscrew driven cam 84 and the mating cam surfaces 94 ofthe articulated jaw 72 hold the articulated jaw in a clampedconfiguration. When the leadscrew driven cam 84 is positioned at thedistal end of the cam slot 86, the rotational position of thearticulated jaw around the pivot pin 88 is unconstrained by theleadscrew driven cam 84 for a range of rotational positions between aclamped configuration (where there is a gap between the leadscrew drivencam 84 and the mating cam surfaces 94 of the articulated jaw 72) and anopen configuration (where there may or may not be a gap between theleadscrew driven cam 84 and the mating cam surfaces 94 of thearticulated jaw 72). For positions of the leadscrew driven cam 84 inbetween the proximal and distal ends of the cam slot 86, the range ofunconstrained motion can vary according to the cam surfaces used.

The use of a recess in each of the proximal sides 100, 102 to define themating cam surfaces 94 of the articulated jaw 72 provides a number ofbenefits. For example, the use of recesses as opposed to traverse slotsthat extend through the proximal sides provides a continuous outsidesurface to the proximal sides 100, 102 of the articulated jaw, which isless likely to snag on patient tissue than would a traverse slotopening. The absence of traverse slots also helps to stiffen theproximal sides 100, 102 as compared to proximal sides with traverseslots, and therefore provides increased clamping stiffness. Suchproximal sides 100, 102 may have increased stiffness in two planes,which may help maintain alignment of the articulated jaw 72 in thepresences of external forces. Such increased stiffness in two planes maybe beneficial in some surgical applications, for example, in tissuestapling where it is beneficial to maintain alignment between thestaples and anvil pockets that form the staples. Further, the use ofrecesses instead of traverse slots also provides an actuation mechanismthat is less likely to be jammed by extraneous material as compared toone having proximal sides with open traverse slots.

The leadscrew actuation mechanism can be configured to provide a desiredclamping force between the articulated jaw and an opposing jaw of theend effector to facilitate cutting or sealing of the tissue. Forexample, in many embodiments, the leadscrew actuation mechanism isconfigured to provide at least 20 lbs of clamping force at the tip ofthe articulated jaw 72 (approximately 2 inches from the pivot pin 88).In many embodiments, the leadscrew actuation mechanism is configured toprovide at least 50 lbs of clamping force at the tip of the articulatedjaw 72. In many embodiments, to produce 50 lbs of clamping force at thetip of the articulated jaw 72, the input torque to the leadscrew 82 isapproximately 0.2 Nm and the leadscrew 82 has 29 turns. The system maydetect the displacement of the motor, of the clamping or firingmechanism or the configuration of the end effector by sensing thedisplacement of the leadscrew. For example, in many embodiments, thesystem is calibrated before starting the procedure so as to determinethe range of motion of both the clamping and the firing mechanism andthe displacement of the leadscrew within that range of motion. Suchcalibration allows the system to determine the configuration of the endeffector or the displacement of the mechanism solely from thedisplacement of the leadscrew.

The leadscrew actuation mechanism can be fabricated using availablematerials and components. For example, many components of the leadscrewactuation mechanism can be fabricated from an available stainlesssteel(s). The leadscrew driven cam 84 can be coated (e.g., TiN) toreduce friction against the surfaces it rubs against (e.g., leadscrew82; end effector base 74; proximal sides 100, 102 of the articulated jaw72). Stranded cables can be used to drive the first actuation mechanism.

FIGS. 8A through 8F illustrate components of a cable actuation mechanism110, in accordance with many embodiments. As described above, theleadscrew driven cam 84 can be positioned at the distal end of the camslot 86 (i.e., near the pivot pin 88). For such a distal position of theleadscrew driven cam 84, as discussed above, the rotational position ofthe articulated jaw 72 about the pivot pin 88 is unconstrained for arange of rotational positions of the articulated jaw 72. Accordingly,the rotational position of the articulated jaw 72 about the pivot pin 88can be controlled by the cable actuation mechanism 110. The cableactuation mechanism 110 is operable to vary the rotational position ofthe articulated jaw between the clamped configuration and the openconfiguration. The cable actuation mechanism 110 includes a pair of pullcables 112, 114. The cable actuation mechanism 110 also includes a firstlinkage 116 that is used to rotate the articulated jaw 72 about thepivot pin 88 towards the clamped configuration, and an analogous secondlinkage 118 that is used to rotate the articulated jaw 72 about thepivot pin 88 towards the open configuration. The first linkage 116(shown in FIGS. 8A and 8B) includes a rotary link 120 that is mountedfor rotation relative to the end effector base 74 via a pivot pin 122. Aconnecting link 124 couples the rotary link 120 to the articulated jaw72 via a pivot pin 126 and a pivot pin 128. The first linkage 116 isarticulated via a pulling motion of the pull cable 112. In operation, apulling motion of the pull cable 112 rotates the rotary link 120 in aclockwise direction about the pivot pin 122. The resulting motion of theconnecting link 124 rotates the articulated jaw 72 in acounter-clockwise direction about the pivot pin 88 towards the clampedconfiguration.

The second linkage 118 (shown in FIGS. 8C through 8F) of the cableactuation mechanism 110 includes analogous components to the firstlinkage 116, for example, a rotary link 130 mounted for rotationrelative to the end effector base 74 via a pivot pin 132, and aconnecting link 134 that couples the rotary link 130 to the articulatedjaw 72 via two pivot pins 136, 138. The second linkage 118 isarticulated via a pulling motion of the pull cable 114. The secondlinkage 118 is configured such that a pulling motion of the pull cable114 rotates the articulated jaw 72 about the pivot pin 88 towards theopen configuration. In many embodiments, the pivot pin 136 between theconnecting link 134 and the rotary link 130 of the second linkage 118 is180 degrees out of phase with the pivot pin 126 between the connectinglink 124 and the rotary link 120 of the first linkage 116. Coordinatedpulling and extension of the pull cables 112, 114 of the cable actuationmechanism 110 is used to articulate the articulated jaw 72 between theopen and clamped configurations. In order to best provide equal andopposite cable motion (and thereby maintain cable tension in acapstan-driven system described below), a common rotational axis for thepivot pins 122, 132 is configured to lie on a plane that contains therotational axes for pivot pins 128, 138 when the articulated jaw 72 isclosed (or nearly closed) and again when the when the articulated jaw 72is open (or nearly open). The connecting links 124, 134 are assembledsymmetrically opposite about this same plane for the first and secondlinkages 116, 118. The distance between the pivot pins 122, 126 andbetween the pivot pins 132, 136 is the same for both the first andsecond linkages 116, 118, and the distance between the pivot pins 126,128 and between the pivot pins 136, 138 is the same for both the firstand second linkages 116, 118.

FIGS. 9A and 9B illustrate an articulation of the articulated jaw 72 viaanother cable actuation mechanism 140, in accordance with manyembodiments. In embodiment 140 of the cable actuation mechanism, a firstpull cable 142 and a second pull cable 144 are directly coupled with theproximal end of the articulated jaw 72. The first pull cable 142 wrapsaround a first pulley 146 so that a pulling motion of the first pullcable 142 rotates the articulated jaw 72 about the pivot pin 88 towardsthe clamped configuration. The second pull cable 144 wraps around asecond pulley 148 so that a pulling motion of the second pull cable 144rotates the articulated jaw 72 about the pivot pin 88 towards the openconfiguration. Accordingly, coordinated pulling and extension of thefirst and second pull cables of the cable actuation mechanism 140 isused to articulate the articulated jaw 72 between the open and clampedconfigurations. In order to best provide equal and opposite cable motion(and thereby maintain cable tension in the capstan-driven systemdescribed below), the radius of the arc prescribed by cable 142 aboutthe pivot 88 is substantially the same as the radius prescribed by cable144 about the pivot 88.

Although the mechanisms may comprise leadscrews, cable or hypotubes,alternate mechanisms can be used to effect clamping or staple firing.For example, an actuation mechanism comprising push/pull rods or springscan be used.

FIG. 10 is a cross-sectional view illustrating components of the abovediscussed leadscrew actuation mechanism. The illustrated componentsinclude the leadscrew 82, the leadscrew driven cam 84, the cam slot 86in the end effector base 74, the distal journal surface 96, thecylindrical receptacle 154 in the end effector base, and the proximalbearing 98 supported by the end effector base 74.

FIG. 11 is a simplified diagrammatic illustration of a tool assembly170, in accordance with many embodiments. The tool assembly 170 includesa proximal actuation mechanism 172, an elongate shaft 174 having aproximal end and a distal end, a tool body 176 disposed at the distalend of the shaft, a jaw 178 movable relative to the tool body 176between a clamped configuration and an open configuration, a firstactuation mechanism coupled with the jaw, and a second actuationmechanism coupled with the jaw. The first actuation mechanism isoperable to vary the position of the jaw relative to the tool bodybetween the clamped configuration and the open configuration. The secondactuation mechanism has a first configuration where the jaw is held inthe clamped configuration and a second configuration where the positionof the jaw relative to the tool body is unconstrained by the secondactuation mechanism. The first actuation mechanism is operativelycoupled with the proximal actuation mechanism. In many embodiments, thefirst actuation mechanism comprises a pair of pull cables that areactuated by the proximal actuation mechanism. The second actuationmechanism is operatively coupled with the proximal actuation mechanism.In many embodiments, the second actuation mechanism includes a leadscrewdriven cam located in the tool body that is driven by the proximalactuation mechanism via a drive shaft extending through the elongateshaft 174164 from the proximal actuation mechanism.

The tool assembly 170 can be configured for use in a variety ofapplications. For example, the tool assembly 170 can be configured as ahand held device with manual and/or automated actuation used in theproximal actuation mechanism. The tool assembly 170 can also beconfigured for use in surgical applications, for example, electrocauterysealing, stapling, etc. The tool assembly 170 can have applicationsbeyond minimally invasive robotic surgery, for example, non-roboticminimally invasive surgery, non-minimally invasive robotic surgery,non-robotic non-minimally invasive surgery, as well as otherapplications where the use of the disclosed redundant jaw actuationwould be beneficial.

Redundant jaw actuation can be used to articulate a jaw of a robotictool end effector. For example, FIG. 12 schematically illustrates arobotic tool 180 employing redundant jaw actuation. The robotic tool 180includes a proximal tool chassis 182, a drive motor 184, an instrumentshaft 186, a distal end effector 188, a first actuation mechanismportion 190, and a second actuation mechanism 192. The distal endeffector 188 comprises an articulated jaw 194. The proximal tool chassis182 is releasably mountable to a robotic tool manipulator 196 having afirst drive 198, and a first actuation mechanism portion 200 thatoperatively couples with the first actuation mechanism portion 190 ofthe robotic tool 180 when the proximal tool chassis 182 is mounted tothe robotic tool manipulator 196. The instrument shaft 186 has aproximal end adjacent the tool chassis 182, and a distal end adjacentthe end effector 188. The first actuation mechanism (comprising portion200 and portion 190) couples the first drive 198 to the articulated jaw194 when the tool chassis 182 is mounted to the tool manipulator 196 soas to articulate the end effector 188 between an open configuration anda clamped configuration. The second actuation mechanism 192 couples thedrive motor 184 to the articulated jaw 194 so as to apply a firing forceto a staple so as to fire the staple from the end effector through thetissue clamped within the jaws of the end effector. The first actuationmechanism can be a leadscrew-driven mechanism that provides relativelyhigh forces so as to fire the staple through the tissue. The secondactuation mechanism can include a drive shaft that couples the drivemotor 184 with a leadscrew actuation mechanism, for example, an abovediscussed leadscrew actuation mechanism that provides the high clampingforce mode. System 180 includes Sensor 193 for monitoring the driveparameters of the first drive 198 and the drive motor 184 duringclamping and firing, respectively. Sensor 193 may also detect thedisplacement of the first drive and the drive motor so as to determinethe acceptable range of desired drive parameters according to a givendisplacement of the motor or configuration of the end effector. Theconfigurations of the end effector in a clamping mode may include anopen configuration, a close/clamped configuration and any configurationtherebetween. The configurations of the end effector in the firing modemay include a pre-firing configuration in which one or more staples aredisposed within the end effector and releasably coupled with the drivemotor 184 through a mechanism and a post-firing configuration where oneor more staples have been fired through the tissue, and typically bentso as to seal the tissue, the staple having been released from the endeffector. The configurations of the end effector may also include anyconfiguration in between the pre-firing and post-firing mode. Bydetecting the displacement of the first drive or drive motor, the sensorcan determine a given configuration of the end effector in either mode,so as to more accurately determine the acceptable range of drivingparameters and predict failure of clamping or firing.

FIG. 13 is a diagrammatic view of a telerobotic surgical system whichincorporates an embodiment of the present invention. In the example ofFIG. 13, a physician inputs a command to the system to clamp a tissue orfire a staple. In response to the user command, the system beginsdriving the motor 210 so as to drive clamping or firing through theclamping and/or firing mechanism 240. As mechanism 240 effects clampingor firing, Processor 220 monitors a drive parameter, such a torqueoutput, of Motor 210. Monitoring may comprise comparing the torqueoutput to an acceptable range of torque outputs for a given displacementof the motor or mechanism. The Processor 220 may be coupled to any orall of the Motor 210, the Mechanism 240 or a Sensor 230 for detecting adisplacement of the motor or mechanism during the clamping or firing. Inresponse to the monitored drive parameter falling outside an acceptablerange of torque outputs (or displacements of the driving mechanism),Processor 220 outputs a Failure Indication 250 on Display 60 of the userinterface, indicating that clamping or firing has failed, or alikelihood of failure. Typically, Display 60 includes images of the endeffector during clamping or firing.

FIGS. 14A-14B illustrate two examples of failure indicator 250 that mayappear on Display 60 of System 10. Typically, the user interface Display60 images and/or visual representations of the surgical tool endeffectors during the surgery in addition to the indicators of clampingor fairing failure. The failure indicator may be superimposed over theimages on the user interface display during the surgical procedure so asto seamlessly incorporate the features of the claimed invention into thesurgical procedure. Preferably, the failure indicator only appears whenthe Surgeon has commanded System 10 to clamp or fire a staple into aclamped tissue. By monitoring the drive parameter, System 10 provides anindication of failure during the procedure. FIG. 14A depicts Display 60with a clamping failure indicator 250 superimposed on the lower rightarea of the screen, wherein the failure indicator 250 indicates thatclamping success is likely and that the system is proceeding to clamp.FIG. 15B depicts Display 60 with failure indicator 250 superimposed onthe lower right area of the screen, wherein the indicator indicates thatclamping will likely fail. Failure indicator 250 is output in responseto the monitored drive parameter driving the clamping being outside thepredetermined range of acceptable drive parameters.

FIG. 15A-15B illustrate additional examples of the clamping predictionindicator 250. FIG. 15A depicts an example of a failure indicatorshowing a likelihood of clamping failure as a gradient, where in thisexample, the likelihood is expressed as a percentage of chance. Forexample, the further outside the range of predetermined drive parametersthe actual monitored drive parameter is, the more likely clampingfailure will be. For example, in one embodiment, if the actual monitoreddriving torque is within 5% of a predetermined target driving torque,the system will display an indicator of 90% likelihood of clampingsuccess. As the monitored driving torque further diverges from thetarget driving torque, the likelihood decreases in a monotonicrelationship, such as from 90% down to a 0% likelihood of clamping.Alternatively, the driving parameter may be the displacement of thedriving mechanism. In such an embodiment, the system may monitor thedisplacement of the driving mechanism and indicate clamping or firingfailure when the displacement is outside a predetermined range ofacceptable displacements. FIG. 15B depicts an embodiment having anindicator which toggles between two settings. When the light of theindicator is lit, likely firing failure is indicated, otherwise firingfailure is not indicated.

FIGS. 16A-16B illustrate graphs of a monitored drive parameter inrelation to an acceptable range of desired drive parameters, inaccordance with many embodiments of the invention. This embodimentillustrates that the system may provide an indication of clamping and/orfiring failure simply from monitoring the torque of the motor as itdrives the clamping or firing of the system. As shown, the predeterminedrange of torques may vary in relation to the displacement of the motoras it effects movement of the end effector. The displacement (s) of themotor may be correlated by the system to a position of the end effectorduring the clamping process. For example, during clamping, as thedisplacement of the motor moves from s_(i) to s_(f), the jaws of the endeffector move from an open configuration to a closed (clamped)configuration. Similarly, the motor displacement may be used to trackthe position or configuration of the end effector during firing of astaple into the clamped tissue. In many embodiments, before performing aprocedure, the system calibrates the jaws of the end effector from afirst to a second configuration, such as calibrating jaws from an openposition to a closed position, so as to correlate the displacement ofthe motor with the configuration of the end effector.

FIG. 16A illustrates a predetermined range of acceptable driving torques(t) which vary with motor displacement (s). The range is delimited bytwo functions, an upper boundary t_(upper) and a lower boundaryt_(lower). The system outputs an indication of clamping failure inresponse to the monitored driving torque T as compared to thepredetermined range of acceptable driving torques. If the displacementof the motor reaches s_(f) and the system has not indicated likelyclamping or firing failure, the system may provide an indication ofsuccessful clamping or firing. In this example, the graph depicts theacceptable range of torques and the monitored driving torque duringclamping or firing as T1. As shown, during the clamping or firing, T1remains within the acceptable range of driving torques, thus the systemwould output an indication that clamping or firing is likely successful(which may include a lack of an indication of failure).

FIG. 16B illustrates a similar predetermined range of acceptable drivingtorques (t) and two separate driving torques, T2 and T3 (occurring atdifferent times). As shown, T2 falls below the lower boundary,t_(lower), of the acceptable range of torques. This may occur where thetissue has slipped out of the jaws of the end effector and less torqueis required to close the jaws since there is no tissue between the jaws.In such case, the system would output an indication of likely clampingfailure at Failure Point F2, at which point the system may suspenddriving of the clamping to prevent any possible tissue damage fromcontinuing to apply the clamping force after failure occurs. Failure mayalso occur if the driving torque exceeds the upper boundary of the rangeof acceptable torques, as shown by monitored torque T3. This may occurwhere jaws have clamped onto a bone and an excessive amount of torque isrequired to reach the closed/clamped configuration, which maypotentially cause tissue damage to the bone or surrounding tissue. Inthis example, the monitored torque exceeds t_(upper) at Failure PointF3, at which point the system may suspend driving of the clamping orfiring to reduce the likelihood of tissue damage. In response todetection of failure, the system may suspend driving of the driveparameter or reverse the driving force to unclamp the tissue, inaddition to providing an indication of failure.

FIGS. 17-19 graphically illustrate embodiments of the claimed methods.FIG. 17 is a simplified representation of exemplary method 300. Method300 includes a step 302 of monitoring a drive parameter of a motordriving a tool to clamp and a step 304 of outputting an indication on auser interface of a likelihood of clamping failure during clamping inresponse to the monitored drive parameter. FIG. 18 is a simplifiedrepresentation of exemplary method 304. Method 304 includes a step 305of monitoring a drive parameter of a motor driving a tool to fire astaple into a clamped material and a step 307 of outputting anindication on a user interface of a likelihood of firing failure duringfiring in response to the monitored drive parameter. FIG. 19 is asimplified representation of a method 310 which further includes thestep 312 of driving a motor to clamp a tissue in response to a userinput to clamp, a step 314 of monitoring a drive parameter of the motorduring clamping of the tissue, a step 316 of outputting an indication ofa likelihood of clamping failure during clamping in response to themonitored drive parameter, and a step 318 of suspending driving of themotor if there is an indication of likely failure or continuing drivingof the motor if there is no indication of likely failure. FIG. 20 is asimplified representation of a method 320 which includes step 322 ofdriving a motor to clamp or fire a staple into a clamped material inresponse to a user input, step 324 of monitoring a drive parameterduring clamping or firing, step 326 of outputting an indication on auser interface of the likelihood of clamping or firing failure duringclamping or firing. If there is no indication of likely failure, thenthe method of 320 further includes step 328 of continuing driving themotor to clamp or fire and step 330 of outputting a message of successwhen clamping or firing complete. If there is an indication of likelyfailure, then the method of 320 further includes step 332 of suspendingdriving of the motor in response to the indication and step 334 ofoutputting an indication that the driving parameter has been suspended.

FIGS. 21-22 depict flowcharts illustrating embodiments of the claimedmethods. FIG. 21 is a flow chart showing an embodiment of the claimedmethod as applied to clamping as it would be incorporated into aminimally invasive robotic surgical system. FIG. 22 is a flow chartshowing an embodiment of the claimed method as applied to firing of astaple into clamped tissue as it would be incorporated into the roboticsurgical system of FIG. 20. The described robotic system may requireuser input to command the system to clamp and/or firing the staple intothe clamped tissue.

It is understood that the examples and embodiments described herein arefor illustrative purposes and that various modifications or changes inlight thereof will be suggested to persons skilled in the art and are tobe included within the spirit and purview of this application and thescope of the appended claims. Numerous different combinations arepossible, and such combinations are considered to be part of the presentinvention.

What is claimed is:
 1. An apparatus comprising: an end effector having afirst jaw and a second jaw for clamping a material, and a staple forstapling the material clamped between the first and second jaws; a drivesystem operatively coupled to the end effector such that driving anactuator of the drive system actuates the end effector for either asurgical or non-surgical method, wherein the drive system moves thefirst jaw toward the second jaw so as to clamp the material between thejaws such that a clamping force is applied, and wherein the drive systemis coupled to the staple such that driving the actuator to stapleproduces a firing force so as to fire the staple into the materialclamped between the first and second jaws; a sensor for monitoring adrive parameter of the drive system when the actuator induces theclamping force, the firing force, or both the clamping force and thefiring force; a processor which continuously monitors the driveparameter of the drive system and compares the drive parameter to anacceptable range of drive parameters as the drive system drives the jawsto clamp at a desired clamping force; and a user interface having anindicator for indicating success or failure of clamping or firing,wherein the indicator is of failure when the drive parameter duringclamping is outside of an acceptable range of desired drive parametersfor clamping or when the drive parameter during firing is outside anacceptable range of desired drive parameters for firing.
 2. Theapparatus of claim 1, wherein the indicator is of a likelihood offailure, wherein the likelihood corresponds to a probability of failureor success of clamping or firing.
 3. The apparatus of claim 1, whereinthe method is non-surgical in nature, and wherein clamping or firingcomprises clamping a compliant material and firing a staple through theclamped compliant material.
 4. The apparatus of claim 1, wherein themethod is surgical in nature and clamping comprises clamping a bodytissue and firing comprises firing a staple into the clamped bodytissue.
 5. The apparatus of claim 4, wherein the tissue comprises any ofan outer skin, a bowel, a stomach, and any internal body organ orstructure.
 6. The apparatus of claim 1, wherein the drive system isoperatively coupled to the end effector by one or more drivingmechanisms.
 7. The apparatus of claim 6, wherein the mechanismscomprises any or all of a cable, hypotube, drive shaft, universal,single or double cardan joint, and a leadscrew.
 8. The apparatus ofclaim 6, wherein the sensor monitors a displacement of the actuator, adisplacement of the one or more driving mechanisms, or both thedisplacement of the actuator and the displacement of the one or moredriving mechanisms.
 9. The apparatus of claim 1, wherein the indicatorcomprises any or all of an audio, visual, or other sensory indicator forcommunication failure to a user on the user interface.
 10. The apparatusof claim 1, wherein the actuator comprises one or more actuators,including any or all of an electric motor, a hydraulic actuator, apneumatic actuator, and a variable torque output actuator.
 11. Theapparatus of claim 1, wherein the processor terminates the clamping orfiring force when the sensor detects that the drive parameter duringclamping or firing is different from the acceptable range of driveparameters for clamping or firing.
 12. The apparatus of claim 1, whereinthe processor terminates the firing force and maintains the clampingforce when the sensor detects the firing force is greater than theacceptable range of firing forces.